Cryptococcal Antigen Latex Agglutination System (CALAS®)

2. Centrifuge at 1000 xg for 15 minutes to ensure the removal of all white cells
and particulate matter.
3. Carefully aspirate the spinal fluid into a sterile container and seal.
4. Specimen may be processed immediately, refrigerated, preserved by
freezing at -20 C or by adding thimerosal to provide a final concentration of
0.01%.
5. We recommend that CSF be inactivated by placing in a boiling water
bath for 5 minutes prior to each test. 7 This tends to limit nonspecific
interference.
6. Allow to cool 3-4 minutes before testing.
B. Serum (It is recommended that all serum specimens be treated with pronase as
described below).
1. Collect whole blood aseptically according to in-house procedures. The
specimen must not contain anticoagulants as this will invalidate the test.
2. Permit blood to clot for 10 minutes or more at room temperature in a
collection tube.
3. Centrifuge at 1000 xg for 15 minutes.
4. Carefully aspirate the serum into a sterile container and seal.
5. Specimen may be processed immediately, refrigerated, preserved by
freezing at -20 C or by adding thimerosal to provide a final concentration of
0.01%.
6. Add 200 µL of serum specimen to 200 µL of the pronase solution.
7. Incubate serum/pronase solution at 56 C for 15 minutes.
8. Immediately boil the serum/pronase solution for a full five minutes to
terminate enzymatic digestion.
9. Allow solution to cool to room temperature.
10. Specimen is ready for testing (see PROCEDURE).
Note: For titering purposes, patient specimen has been diluted 1:2 with the pronase
solution.
C. Negative Control – Heat inactivate the Negative Control at 56 C for 30
minutes. It must be heat inactivated each day of use.
7